Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond readOnlyHint/openWorldHint, it discloses the data provenance, the 404 failure mode, and the paid-call semantics ($0.002 USDC per successful call via x402 on Base/Solana/Arc, failed calls not charged). That payment and error behavior is exactly the context annotations cannot express.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One front-loaded paragraph that leads with what the tool returns, then input forms, error behavior, and pricing. It is dense and nearly waste-free; the long field enumeration is useful but slightly pushes length.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema covering return values, a fully documented single parameter, and annotations covering the safety profile, the description closes the remaining gaps: provenance, 404 behavior, and pricing/payment mechanics.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single parameter is already fully documented in the schema with both accepted formats. The description restates the same ID-or-URL acceptance without adding syntax, validation, or edge cases beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('TikTok sound (music) stats') plus the exact source ('TikTok's public embed player and sound page') and enumerates the returned fields. An agent can tell precisely what this tool yields without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear operating context: accepts a sound ID or a tiktok.com/music/… URL, and unknown sounds return 404. It does not name an alternative tool or an explicit exclusion, but none of the siblings covers TikTok sound data, so the lack of routing guidance is low-cost.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.